[darcs-users] Fwd: Darcs Problems

[Stephen J. Turnbull]

Ben Franksen writes:

 > In Darcs, repo==branch.

The OP undoubtedly wants colocated branches which are fast and very
lightweight.  OTOH, many of the things I use fast branching for in git
projects simply don't come up under Darcs' model of the world -- I'd
use cherrypicking instead.

 > No problem, as 'darcs get' gives you a new copy of the sources.

This is slow and requires changing directories to work, not to mention
a "make world" rather than a "make one .o and relink".  Darcs has
gotten somewhat faster since I used it with XEmacs, but making a new
branch was annoyingly slow back then (and I only had a couple hundred
patches when the project switched to Mercurial), and any merge could
take forever.  I can't say that I wouldn't have found an efficient and
comfortable workflow (my experiment with XEmacs in Darcs only lasted
about 4 months), but there's no question that I found it quite
constraining (aka "unnatural") compared to git or hg.

 > I find Darcs extremely nice to use (but I have not used git before so I 
 > cannot compare). But one needs to understand the change-oriented model of 
 > Darcs: in Darcs, a repo is a set of changes. In git, a repo is a graph of 
 > versions (if I understood it correctly). In a version-graph, it makes sense 
 > to 'switch' between 'places' in the graph. In a set of changes this is not 
 > such a natural operation.

I don't see why not.  Tom Lord (the great Grampaw of modern open
source VC) used to argue that your VCS is the right place to do many
kinds of configuration.  For example, you don't want PostgreSQL
bindings in this instance of your app?  Unapply the "PostgreSQL patch
set" and rebuild.  This doesn't happen to correspond to Darcs very
well (since it doesn't really have a notion of feature = patch set),
but that's a limitation of Darcs, not of repo-as-a-set-of-changes.
(That line of development didn't work out very well, but it's not
clear to me that it wasn't more for lack of effort on Tom's part than
any defect in the idea itself.)